PROJECT SUMMARY/ABSTRACT This patient-oriented research R21 application will provide funding support for validating a novel approach for assessing functional capacity among hospitalized older adults with chronic obstructive pulmonary disease (COPD), an area of substantial and increasing significance. Our proposed innovative screening method is objective, quick, and based on muscle performance assessment of underlying systemic dynapenia. Within this project we will perform a 90-day longitudinal study to validate prediction of COPD exacerbations, hospitalizations, and mortality using the proposed method. The proposed functional capacity assessment method incorporates an upper-extremity function (UEF) test, to obviate the need for walking tasks in bed-bound hospitalized elders. The UEF test involves repetitive elbow flexion measured using low-cost sensors, which is easily performed (standing, sitting, or in bed) in less than one minute. Post-processing, and scoring will be performed in less than one minutes using an app on laptop or cellphone. We have patented and validated the UEF test for assessing frailty based on motion (kinematics) data, and its feasibility has previously been demonstrated in pilot outpatient and inpatient participants. Within this project, implementing the same hardware and measurement protocol, we will improve the algorithm to assess muscle deconditioning (dynapenia) using a new muscle model that will be added to our original UEF algorithm. The proposed approach builds upon pilot research among COPD patients, performed by an excellent group of interdisciplinary investigators at the University of Arizona Center on Aging and the Arizona Respiratory Science Center, demonstrating significant associations between UEF speed (and embedded strength parameters) with the 6-minute walk distance (6MWD) test, the most commonly used measure of functional capacity in COPD. The goal of this R21 project is to: 1) Develop and evaluate an upper-extremity muscle model; and 2: (Clinical Study): Longitudinally assess UEF validity for predicting 90-day adverse health events among 120 COPD-related hospitalized older adults (? 65 years) ? Predictive Index development and assessment of UEF accuracy, feasibility, and reliability. We expect to extend scientific knowledge regarding the nature of muscle deconditioning (dynapenia) associated with COPD, focusing on an upper-extremity function measure (rather than gait assessment). From a clinical viewpoint, we expect to validate a quick and accurate objective tool for assessing functional capacity among COPD patients as an alternative to the 6MWD test, with the ultimate goal of providing a quick and cost-effective screening tool to support acute and outpatient elders? risk stratification. If demonstrated effective, we expect that this tool could be used to predict those at highest risk, to enable personalized COPD care and support the quality of life and independence of older adults with COPD or multiple chronic conditions.